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- Effects of using live grass shrimp (Palaemonetes varians) as the only source of food for the culture of cuttlefish, Sepia officinalis (Linnaeus, 1758)Publication . Sykes, António V.; Domingues, Pedro M.; Andrade, José PedroThe life cycle of cuttlefish fed ad libitum exclusively on live grass shrimp (Palaemonetes varians) was studied during 5 consecutive generations. Different culture temperatures promoted different (P < 0.05) exponential growth for each life cycle, being summer generations shorter than those of winter. Higher temperatures promoted higher IGR’s and mortality, while lower temperatures promoted increased life span, reproduction stages, total fecundity and total egg biomass. Increased generations also seemed to increase fertility. A ‘‘hybrid’’ generation promoted the best results in terms of hatchling weight, individual fecundity and fertility. Mean egg weight was related to female size and embryonic development took longer at lower temperatures. Brood stock sex ratios seemed to be temperature related.All of these culture aspects were also compared between themselves in order to establish future brood stock methodologies. Grass shrimp proved to be a good diet for the culture of cuttlefish throughout the life cycle. The use of only one species reduces costs and labor associated to cuttlefish culture.
- The use of Artemia sp. or mysids as food source for hatchlings of the cuttlefish (Sepia officinalis L.); effects on growth and survival throughout the life cyclePublication . Domingues, Pedro M.; Sykes, António V.; Andrade, José PedroTwo experiments were conducted to determine the effects of Artemia sp. or mysids on growth and survival of S. offıcinalis hatchlings, and their effect throughout the life cycle. For experiment I, for the first 20 days, one group was fed adult Artemia sp. and the other was fed mysid shrimp (Paramysis nouvelli). Eggs laid by females in both groups were counted and weighed, and hatchlings were weighed, to determine differences in both groups. For experiment II, during the first 10 days, one group was fed Artemia sp. and the other was fed mysids (P. nouveli). After the period of differentiated feeding, the 2 groups in experiment I were fed grass shrimp (Paleomonetes varians) to 70 days old, and dead crabs (Carcinus maenas) afterwards. Cuttlefish in experiment II were fed grass shrimp from day 10 until the end of the experiment. For both experiments, hatchlings fed mysids grew significantly bigger (p < 0.01) and survival was higher. For experiment I, eggs laid by females fed mysids and the hatchlings born from these eggs were bigger (p < 0.001) compared to the group fed Artemia sp. initially. Individual fecundity was slightly higher for females in the group fed Artemia sp. (163 eggs female−1) than for the group fed mysids (144 eggs female−1). Egg laying started at the age of 125 days and lasted 45 days in both groups. Time between first egg laying day and first hatchlings to be born was 21 days. The last female to die (after spawning) in both groups was 167 days (less than 6 months old).